+/*
+avrdude -p atmega168p -P usb -c avrispmkii -U lfuse:w:0xe2:m -U hfuse:w:0xdf:m -U efuse:w:0xf9:m
+-> it failed but I answered y, then make reset and it was ok
+*/
+
#include <aversive.h>
+#include <aversive/wait.h>
struct servo {
uint8_t bit;
static struct servo servo_table[] = {
{
- .bit = 0,
- .command = 0,
+ .bit = 2,
+ .command = 300,
+ },
+ {
+ .bit = 3,
+ .command = 700,
},
{
- .bit = 1,
+ .bit = 4,
.command = 512,
},
{
- .bit = 2,
- .command = 1023,
+ .bit = 5,
+ .command = 512,
+ },
+ {
+ .bit = 6,
+ .command = 512,
+ },
+ {
+ .bit = 7,
+ .command = 512,
},
};
-#define NB_SERVO (sizeof(servo_table)/sizeof(*servo_table))
+#define N_SERVO (sizeof(servo_table)/sizeof(*servo_table))
+
+/* we use the first servo for PPM output if enabled */
+#define PPM (0)
+
+static uint8_t bypass;
+static uint8_t ppm_enabled;
+static volatile uint8_t done;
+static uint8_t portval;
+static uint8_t rxidx;
-register uint8_t bypass asm("r2");
-register uint8_t done asm("r3");
-register uint8_t portval asm("r4");
-register uint8_t rxidx asm("r5");
-#define BYPASS_ENABLE 14
-#define BYPASS_DISABLE 15
+static uint8_t icp_idx = N_SERVO;
+static uint16_t icp_servos[N_SERVO];
+static uint16_t icp_prev;
+
+static uint8_t spi_out_idx; /* current byte beeing sent */
+
+#define PPM_BIT 0x01
+#define BYPASS_BIT 0x02
+
+#define LED_ON() do { PORTB |= 0x02; } while(0)
+#define LED_OFF() do { PORTB &= ~0x02; } while(0)
/*
* SPI protocol:
*
- * A command is stored on 2 bytes. The first one has its msb to 0, and the
- * second one to 1. The first received byte contains the command number, and the
- * msb of the servo value. The second byte contains the lsb of the servo value.
+ * A command is stored on 2 bytes (except command 0). The first byte
+ * has its most significant bit to 0, and the second one to 1. The
+ * first received byte contains the command number, and the msb of the
+ * servo value. The second byte contains the lsb of the servo value.
*
- * Commands 0 to NB_SERVO are to set the value of servo.
- * Command 14 is to enable bypass mode.
- * Command 15 is to disable bypass mode.
+ * Command 0 is only one byte long, it means "I have nothing to say".
+ * Commands 1 to N_SERVO (included) are to set the value of servo.
+ * Command N_SERVO+1 is:
+ * - to enable/disable ppm generation in place of first servo.
+ * - to enable/disable bypass mode
*/
-register union {
+union byte0 {
uint8_t u8;
struct {
- uint8_t zero:1;
- uint8_t cmd_num:4;
+ /* inverted: little endian */
uint8_t val_msb:3;
+ uint8_t cmd_num:4;
+ uint8_t zero:1;
};
-} byte0 asm("r6");
+};
-register union {
+union byte1 {
uint8_t u8;
struct {
- uint8_t one:1;
+ /* inverted: little endian */
uint8_t val_lsb:7;
+ uint8_t one:1;
};
-} byte1 asm("r7");
+};
SIGNAL(TIMER1_COMPA_vect)
{
- PORTC = portval;
+ PORTD = portval;
TIMSK1 &= ~_BV(OCIE1A);
done = 1;
}
static void poll_spi(void)
{
uint8_t c;
+ uint16_t servo;
+ static union byte0 byte0_rx;
+ union byte1 byte1_rx;
+ union byte0 byte0_tx;
+ static union byte1 byte1_tx;
/* reception complete ? */
if (!(SPSR & (1<<SPIF)))
return;
c = SPDR;
+
+ /* prepare next TX */
+
+ if ((spi_out_idx & 1) == 0) {
+ servo = icp_servos[spi_out_idx >> 1];
+ byte0_tx.val_msb = servo >> 7;
+ byte0_tx.cmd_num = (spi_out_idx >> 1) + 1;
+ byte0_tx.zero = 0;
+ byte1_tx.val_lsb = servo & 0x7f;
+ byte1_tx.one = 1;
+ SPDR = byte0_tx.u8;
+ }
+ else {
+ SPDR = byte1_tx.u8;
+ }
+ spi_out_idx ++;
+ if (spi_out_idx >= N_SERVO * 2)
+ spi_out_idx = 0;
+
+ /* RX */
+
if ((rxidx == 0) && (c & 0x80)) {
rxidx = 0;
return; /* drop */
}
if (rxidx == 0) {
- byte0.u8 = c;
+ byte0_rx.u8 = c;
+
+ /* command num 0 is ignored */
+ if (byte0_rx.cmd_num == 0)
+ return;
}
else {
uint16_t val;
- byte1.u8 = c;
+ byte1_rx.u8 = c;
/* process command */
- if (byte0.cmd_num < NB_SERVO) {
- val = (uint16_t)byte0.val_msb << 7;
- val += byte1.val_lsb;
- servo_table[byte0.cmd_num].command = val;
- }
- else if (byte0.cmd_num == BYPASS_ENABLE) {
- bypass = 1;
+ val = (uint16_t)byte0_rx.val_msb << 7;
+ val += byte1_rx.val_lsb;
+
+ if (byte0_rx.cmd_num < N_SERVO+1) {
+ servo_table[byte0_rx.cmd_num-1].command = val;
}
- else if (byte0.cmd_num == BYPASS_DISABLE) {
- bypass = 0;
+ else if (byte0_rx.cmd_num == N_SERVO+1) {
+ if (val & PPM_BIT)
+ ppm_enabled = 1;
+ else
+ ppm_enabled = 0;
+ if (val & BYPASS_BIT)
+ bypass = 1;
+ else
+ bypass = 0;
}
}
rxidx ^= 1;
}
+static void poll_input_capture(void)
+{
+ uint16_t icp, diff;
+
+ /* no new sample, return */
+ if ((TIFR1 & _BV(ICF1)) == 0)
+ return;
+
+ cli();
+ icp = ICR1;
+ sei();
+
+ /* clear the flag by writing a one */
+ TIFR1 = TIFR1 | _BV(ICF1);
+
+ diff = icp - icp_prev;
+ icp_prev = icp;
+
+ /* a rising edge with at least 2ms of state 0 means that we
+ * get the first servo */
+ if (diff > 3000) {
+ icp_idx = 0;
+ return;
+ }
+
+ /* get the value for the servo */
+ if (icp_idx < N_SERVO) {
+ if (diff < 1000)
+ icp_servos[icp_idx] = 0;
+ else if (diff > 2023)
+ icp_servos[icp_idx] = 1023;
+ else
+ icp_servos[icp_idx] = diff - 1000;
+ icp_idx++;
+ }
+}
+
+static void poll(void)
+{
+ poll_spi();
+ poll_input_capture();
+}
+
static void load_timer_at(uint16_t t)
{
OCR1A = t;
TIMSK1 |= _BV(OCIE1A);
}
-static void do_one_servo(struct servo *s)
+static void do_servos(void)
{
- uint16_t t;
+ uint8_t i;
+ uint16_t t, start;
+
+ /* skip first servo if ppm is enabled */
+ if (ppm_enabled)
+ i = 1;
+ else
+ i = 0;
- /* set bit */
- done = 0;
- //portval = PORTC | (1 << s->bit);
- portval = (1 << s->bit);
t = TCNT1;
- load_timer_at(t + 150);
- while (done == 0)
- poll_spi();
+ start = t + 100;
+
+ for (; i < N_SERVO; i++) {
+
+ /* set servo and PPM bit */
+ portval = 1 << servo_table[i].bit;
+ if (ppm_enabled)
+ portval |= (1 << servo_table[PPM].bit);
+
+ done = 0;
+ load_timer_at(start);
+ while (done == 0)
+ poll();
+
+ /* reset PPM bit after 300us */
+ portval = 1 << servo_table[i].bit;
+ done = 0;
+ load_timer_at(start + 300);
+ while (done == 0)
+ poll();
+
+ start = start + 1000 + servo_table[i].command;
+ }
+
+ /* set PPM bit only for last servo */
+ portval = 0;
+ if (ppm_enabled)
+ portval |= (1 << servo_table[PPM].bit);
- /* reset bit */
done = 0;
+ load_timer_at(start);
+ while (done == 0)
+ poll();
+
+ /* reset PPM bit after 300us */
portval = 0;
- //portval = PORTC & (~(1 << s->bit));
- load_timer_at(t + 150 + 8000 + s->command * 8);
+ done = 0;
+ load_timer_at(start + 300);
while (done == 0)
- poll_spi();
+ poll();
}
int main(void)
{
- uint8_t i;
uint8_t t, diff;
+ uint8_t tmp;
+ uint8_t cnt = 10;
+
+ /* use pull-up for inputs */
+ PORTC |= 0x3f;
/* LED */
- DDRB = 0x20;
+ DDRB = 0x02;
- /* servo outputs */
- DDRC = 0x7;
+ while (cnt > 0) {
+#if 1 /* disable for LED debug only */
+ cnt--;
+#endif
+ LED_ON();
+ wait_ms(100);
+ LED_OFF();
+ wait_ms(100);
+ }
+
+ /* servo outputs PD2-PD7 */
+ DDRD = 0xfc;
- /* start timer1 at clk/1 (8Mhz) */
+ /* start timer1 at clk/8 (1Mhz), enable noise canceler on
+ * input capture, capture rising edge */
TCNT1 = 0;
- TCCR1B = _BV(CS10);
+ TCCR1B = _BV(CS11) | _BV(ICNC1) | _BV(ICES1);
/* start timer0 at clk/1024 (~8Khz) */
TCNT0 = 0;
TCCR0B = _BV(CS02) | _BV(CS00);
- /* enable spi (don't set unused MISO as output) */
+ /* enable spi (set MISO as output) */
SPCR = _BV(SPE);
+ SPDR = 0;
+ DDRB |= _BV(4);
sei();
bypass = 0;
while (1) {
t = TCNT0;
- for (i = 0; i < NB_SERVO; i++) {
- do_one_servo(&servo_table[i]);
- }
+ do_servos();
/* wait 20 ms */
while (1) {
diff = TCNT0 - t;
if (diff >= 160)
break;
- poll_spi();
+ poll();
}
/* bypass mode */
- while (bypass == 1) {
- PORTC = PORTB;
+ if (bypass == 1) {
+ LED_ON();
+
+ while (bypass == 1) {
+ tmp = PINC;
+ tmp &= 0x3f;
+ tmp <<= 2;
+ PORTD = tmp;
+ poll();
+ }
+ LED_OFF();
}
}
git.droids-corp.org / protos / rc_servos.git / blobdiff